HANSCOM AIR FORCE BASE, Mass. -- One of the most dangerous threats facing the Department of Defense is the insider threat.

Individuals committing espionage have consistently demonstrated certain "indicators." Although these behaviors were observed by fellow workers, they failed to report them.

Some of the most common reportable indicators include:

- An attempt to obtain information without having a genuine "need to know."

- Repeated, unusual or unnecessary overtime.

- Unauthorized removal of classified, sensitive, or proprietary information from a work place.

- Repeatedly being caught bringing electronic devices into sensitive work areas.

- Excessive hoarding of sensitive information.

- A network user account identified as using an excessive amount of storage space.

- Printing an abnormally high volume of documents.

- Sending an abnormal amount of emails containing large file attachments.

- Sudden purchase of high-value personal items for which no logical source of income exists.

- Extensive or regular gambling losses or financial indebtedness.

- The employee, after returning from travel, has a difficult time describing travel details.

- Employee's demeanor suddenly changes for the worse: he or she becomes disgruntled, depressed, angry, moody, short-tempered, sad, a loner, or develops a defeatist attitude.

If you have concerns about a co-worker exhibiting this type of behavior, contact your unit security manager or the local Air Force Office of Special Investigations at Hanscom at 781-225-5861.